Diagnosis method, charged particle beam lithography apparatus, and recording medium

ABSTRACT

Disclosed is a method of diagnosing a conversion process for converting a format of image data including unit data corresponding to charged particle beams into a format suitable for an aperture array, the aperture array having a plurality of controllers provided to match a plurality of the charged particle beams to control the charged particle beams, and a driver configured to drive the controllers. The method includes: extracting the unit data having an identical first rank based on an arrangement of the unit data in the image data from the unit data of each block including a predetermined number of the unit data and calculating a first checksum of each of the first rank; extracting the unit data having an identical second rank after the conversion process from the unit data of each block and calculating a second checksum of each of the second rank; and comparing the first and second checksums.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Applications No. 2016-032249 filed in Japan onFeb. 23, 2016; the entire contents of which are incorporated herein byreference.

FIELD

The present disclosure relates to a diagnosis method, a charged particlebeam lithography apparatus, and a recording medium.

BACKGROUND

In a semiconductor device lithography process, an original patternformed on a mask is transferred to a wafer serving as a substrate of thesemiconductor device. Drawing of the original pattern onto the mask isperformed, for example, using an electron beam lithography apparatus.

In recent years, in order to improve a throughput, a multi-beam typeelectron beam lithography apparatus capable of drawing a pattern using aplurality of electron beams has come into use. In such a type of theelectron beam lithography apparatus, an electron beam emitted from asingle electron source is divided into multiple beams (multiplexed) asthe electron beam passes through an aperture having a plurality ofholes. The ON/OFF control of multiple electron beams are independentlyperformed, for example, by a blanking aperture array (BAA).

Since the BAA is disposed in a vacuum lens barrel provided with anelectron gun or the like for emitting an electron beam, its size isrestricted. For this reason, a data format processed by the BAA isselected such that a control circuit of the BAA becomes as simple aspossible. Meanwhile, image data of the pattern drawn by the electronbeam lithography apparatus is designed, for example, using acomputer-aided design (CAD) tool and is output in a bitmap format.

In order to perform the ON/OFF control of the electron beam using theBAA, it is necessary to convert the image data representing the patternto be drawn into a format suitable for an interface of the BAA.

If an error occurs in conversion of the image data described above, aproduct yield is degraded. Thus, various techniques for avoiding such apatterning error have been proposed.

In the prior art, an error of the drawing data is detected by comparinga checksum of the data obtained before being supplied to the BAA and achecksum of the data supplied to the BAA. In the technique of JPH08-297586 A, a damage of the drawing data is detected by calculatingand comparing an expected parity bit of the data obtained after sorting.In the technique of JP H09-74060 A (corresponding to U.S. Pat. No.5,866,300), however, it is difficult to detect a conversion error whilethe damaged data can be detected. In the technique of JP H08-297586 A,for example, if a conversion error occurs due to a change of the dataarrangement sequence, a parity check may be successful erroneously.Thus, it is difficult to detect abnormality. For this reason, if aconversion error described above occurs, a long time is necessary toperform troubleshooting. As a result, a system downtime may beprolonged.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a configuration of anelectron beam lithography apparatus according to an embodiment of thedisclosure;

FIG. 2 is a top plan view illustrating an aperture;

FIG. 3 is a perspective view illustrating an electron gun, a lens, anaperture, and an aperture array;

FIG. 4 is a top plan view illustrating the aperture array;

FIG. 5 is an enlarged perspective view illustrating a blanker;

FIG. 6 is a wiring diagram illustrating a converter and a blanker;

FIG. 7 is a block diagram illustrating a controller;

FIG. 8 is a connection diagram illustrating a BAA controller and theconverter;

FIG. 9 is a diagram illustrating a unit pattern drawn on the basis ofimage data;

FIG. 10 is a diagram illustrating a circuit pattern including the unitpattern;

FIG. 11 is a schematic diagram illustrating the image data;

FIG. 12 is a diagram for describing a drawing process of the circuitpattern;

FIG. 13 is a diagram for describing a drawing process of the circuitpattern;

FIG. 14 is a diagram for describing a drawing process of the circuitpattern;

FIG. 15 is a diagram for describing a drawing process of the circuitpattern;

FIG. 16 is a diagram for describing a drawing process of the circuitpattern;

FIG. 17 is a diagram for describing a drawing process of the circuitpattern;

FIG. 18 is a schematic diagram illustrating serial data based on imagedata;

FIG. 19 is a diagram for describing a drawing process of the circuitpattern;

FIG. 20 is a diagram for describing a drawing process of the circuitpattern;

FIG. 21 is a diagram for describing a drawing process of the circuitpattern;

FIG. 22 is a diagram for describing a drawing process of the circuitpattern;

FIG. 23 is a schematic diagram illustrating serial data based on imagedata;

FIG. 24 is a flowchart illustrating an error diagnosis process;

FIG. 25 is a diagram for describing a process of calculating a checksumfor each arrangement rank of unit data;

FIG. 26 is a supplemental diagram for describing a method of calculatinga checksum;

FIG. 27 is a diagram for describing a process of calculating a checksumaccording to a sorting rule;

FIG. 28 is a supplemental diagram for describing a method of calculatinga checksum;

FIG. 29 is a diagram for describing a process of comparing the checksum;

FIG. 30 is a diagram for describing a process of comparing the checksum;

FIG. 31 is a diagram for describing a process of comparing the checksum;

FIG. 32 is a diagram conceptually illustrating original image data andimage data equivalent to serial data;

FIG. 33 is a schematic diagram illustrating unit data; and

FIG. 34 is a diagram for describing a bit data exchange process.

DETAILED DESCRIPTION

In accordance with an aspect of the present disclosure, there isprovided a method of diagnosing a conversion process for converting aformat of image data including unit data corresponding to chargedparticle beams into a format suitable for an aperture array, theaperture array having a plurality of controllers provided to match aplurality of the charged particle beams to control the charged particlebeams and a driver configured to drive the controllers, the methodincluding: extracting the unit data having an identical first rank basedon an arrangement of the unit data in the image data from the unit dataof each block including a predetermined number of the unit data andcalculating a first checksum of each of the first rank; extracting theunit data having an identical second rank after the conversion processfrom the unit data of each of the blocks and calculating a secondchecksum of each of the second rank; and comparing the first and secondchecksums.

In accordance with another aspect of the present disclosure, there isprovided a charged particle beam lithography apparatus including: anaperture array having a plurality of controllers provided to match aplurality of charged particle beams to control the charged particlebeams and a driver configured to drive the controllers; a converterconfigured to convert a format of image data having unit datacorresponding to the charged particle beams into a format suitable forthe aperture array; a first calculator configured to extract the unitdata having an identical first rank based on the arrangement of the unitdata of the image data from the unit data of each block having apredetermined number of the unit data and calculate a first checksum foreach of the first rank; a second calculator configured to extract theunit data having an identical second rank after the conversion of theconverter from the unit data of each of the blocks and calculate asecond checksum for each of the second ranks; and a first comparatorconfigured to compare the first checksum with the second checksum.

A computer-readable recording medium storing a program for diagnosing aconversion process for converting a format of image data including unitdata corresponding to charged particle beams into a format suitable foran aperture array, the aperture array having a plurality of controllersprovided to match a plurality of the charged particle beams to controlthe charged particle beams, and a driver configured to drive thecontrollers, the program causing a computer to execute: extracting theunit data having an identical first rank based on an arrangement of theunit data in the image data from the unit data of each block including apredetermined number of the unit data and calculating a first checksumof each of the first rank; extracting the unit data having an identicalsecond rank after the conversion process from the unit data of each ofthe blocks and calculating a second checksum of each of the second rank;and comparing the first checksum with the second checksum.

Embodiments of the present disclosure will be described below withreference to the accompanying drawings. In the description of theembodiments, a Cartesian coordinate system composed of X, Y, and Z axesperpendicular to each other is appropriately employed.

<Configuration of Apparatus>

FIG. 1 is a schematic diagram illustrating a configuration of anelectron beam lithography apparatus 10 according to an embodiment of thedisclosure. The electron beam lithography apparatus 10 is an apparatusfor drawing a pattern using an electron beam on a specimen 120 such as amask or reticle coated with a resist material under the vacuumenvironment.

As illustrated in FIG. 1, the electron beam lithography apparatus 10includes an irradiator 20 that irradiates an electron beam EB onto thespecimen 120, a stage 70 used to place the specimen 120, a vacuumchamber 80 that houses the irradiator 20 and the stage 70, and a controlsystem 100 that controls the irradiator 20 and the stage 70.

The vacuum chamber 80 includes a writing chamber 80 a that houses thestage 70 and a lens barrel 80 b that houses the irradiator 20.

The writing chamber 80 a is a rectangular parallelepiped hollow memberand has a circular opening on its upper surface. The lens barrel 80 b isa cylindrical casing whose longitudinal direction is parallel to theZ-axis direction. The lens barrel 80 b is formed of, for example,stainless steel and is grounded. The lens barrel 80 b is inserted intothe inside of the writing chamber 80 a from the opening provided on theupper surface of the writing chamber 80 a. The internal vacuum levels ofthe writing chamber 80 a and the lens barrel 80 b are maintained, forexample, at approximately 10⁻⁷ Pa.

The irradiator 20 includes an electron gun 30, lenses 41, 42, and 43,apertures 51 and 52, an aperture array 61, and a deflector 62. Theelectron gun 30, the lenses 41, 42, and 43, the apertures 51 and 52, theaperture array 61, and the deflector 62 are disposed inside the lensbarrel 80 b.

The electron gun 30 is disposed in an upper part inside the lens barrel80 b. The electron gun 30 is, for example, a hot cathode type electrongun. The electron gun 30 includes a cathode, a Wehnelt electrodeprovided to surround the cathode, an anode disposed under the cathode,and the like. When a voltage is applied, the electron gun 30 ejects theelectron beam EB downward.

The lens 41 is an annular electromagnetic lens and is disposed under theelectron gun 30. The lens 41 shapes the electron beam EB spreadingdownward so as to be parallel to a vertical direction.

The aperture 51 is a member for branching the incident electron beam EBinto a plurality of electron beams EBmn. FIG. 2 is a top plan viewillustrating the aperture 51. As illustrated in FIG. 2, the aperture 51is a rectangular plate-shaped member. The aperture 51 is formed of, forexample, a silicon-based material, and has a surface provided with acoating layer or a sputtering layer formed of, for example, chromium orthe like. The aperture 51 has sixty four holes H arranged in aneight-row and eight-column matrix shape by setting a row direction tothe X-axis direction and setting a column direction to the Y-axisdirection. The hole H has a square shape whose each side is parallel tothe X-axis or Y-axis. The dimensions of the holes H are approximatelyequal to each other in the X-axis and Y-axis directions.

In this embodiment, the sixty four holes H are expressed as “Hmn,” where“m” and “n” denote integers 1 to 8. The hole located in the first rowclosest to zero in the Y-axis direction is denoted by “H1 n.” The holeslocated in the second to eighth rows are denoted by “H2 n” to “H8 n.”The hole located in the first column closest to zero in the X-axisdirection is denoted by “Hm1.” The holes located in the second to eighthcolumns are denoted by “Hm2” to “Hm8.”

FIG. 3 is a perspective view illustrating the electron gun 30, the lens41, the aperture 51, and the aperture array 61. As illustrated in FIG.3, the electron beam EB ejected from the electron gun 30 is shaped bythe lens 41 in parallel to the vertical axis. The shaped electron beamEB is incident to a circular area C1 indicated by a virtual line on theupper surface of the aperture 51. A part of the electron beams EBincident to the area C1 are blocked by the aperture 51, and theremaining electron beams EB pass through the holes Hmn of the aperture51. As a result, the electron beam EB is divided (multiplexed) into 64electron beams traveling vertically downward.

In this embodiment, the electron beam passing through the hole Hmn ofthe aperture 51 will be referred to as an electron beam EBmn. Note that,in FIG. 3, only the electron beams EB11, EB18, EB81, and EB88 passingthrough the holes H11, H18, H81, and H88, respectively are shownrepresentatively.

The aperture array 61 is a unit for individually blanking each electronbeam EBmn. FIG. 4 is a top plan view illustrating the aperture array 61.As illustrated in FIG. 4, the aperture array 61 includes a substrate 610and sixty four blankers BK provided on the upper surface (+Z-sidesurface) of the substrate 610.

The substrate 610 is a square substrate formed of, for example, silicon.The substrate 610 has sixty four holes HH arranged in an eight-row andeight-column matrix shape. Each of the sixty four holes HH is positionedunder each of the holes H of the aperture 51. In this embodiment, theholes HH immediately under the holes Hmn will be expressed as “holesHHmn.”

The hole HHmn is slightly larger than the hole Hmn. The electron beamEBmn passing through the hole Hmn can pass through the hole HHmn withoutinterference of the substrate 610.

FIG. 5 is an enlarged perspective view illustrating the blanker BK. Theblanker BK includes a pair of electrodes 611 and 612 formed of, forexample, metal such as copper. The electrode 611 is a member having aU-shaped X-Y cross section. The electrode 611 is disposed along the+X-side outer edge, the −X-side outer edge, and the +Y-side outer edgeof the hole HHmn provided in the substrate 610. The electrode 612 is aplate-shaped electrode and is disposed along the −Y-side outer edge ofthe hole HHmn. As shown in FIG. 5, the electron beam EBmn passingthrough the aperture 51 passes through a gap between the electrodes 611and 612 of the blanker BK and is then incident to the hole HHmn of thesubstrate 610.

As illustrated in FIG. 4, the blanker BK is provided in each hole HHmn.In this embodiment, the blanker BK provided in the hole HHmn will beexpressed as a blanker BKmn.

The electrode 611 of the blanker BK of FIG. 5 is grounded through acircuit (not illustrated) provided in the substrate 610. In addition, asa voltage is applied to the electrode 612, the electron beam EBmnincident to the hole HHmn of the substrate 610 is deflected in thedirection indicated by the arrow in FIG. 5. As a result, as illustratedin FIG. 1, the electron beam EBmn is blocked by the aperture 52, and theelectron beam EBmn has a blanked state.

FIG. 6 is a wiring diagram illustrating converters 621 to 628 andblankers BK11 to BK88. As shown in FIG. 6, in the aperture array 61, theelectrodes 612 of the blankers BK11 to BK14 and BK21 to BK24 areconnected to the converter 621 through the shift registers SR1 and SR2and the buffer BF. Similarly, the electrodes 612 of the blankers BK31 toBK34 and BK41 to BK44 are connected to the converter 622. The electrodes612 of the blankers BK51 to BK54 and BK61 to BK64 are connected to theconverter 623. The electrodes 612 of the blankers BK71 to BK74 and BK81to BK84 are connected to the converter 624. The electrodes 612 of theblankers BK15 to BK18 and BK25 to BK28 are connected to the converter625. The electrodes 612 of the blankers BK35 to BK38 and BK45 to BK48are connected to the converter 626. The electrodes 612 of the blankersBK55 to BK58 and BK65 to BK68 are connected to the converter 627. Theelectrodes 612 of the blankers BK75 to BK78 and BK85 to BK88 areconnected to the converter 628.

The converters 621 to 628 are converters for converting serial data intoparallel data. The converters 621 to 628 converts the serial data outputfrom the control system 100 into parallel data including four data andoutputs the four data. These data are output through four output linesL1 to L4. The operations of the converters 621 to 628 will be describedbelow.

Returning to FIG. 1, the lens 42 is an annular electromagnetic lens andis disposed under the aperture array 61. The lens 42 makes the sixtyfour electron beams EBmn, that are parallelized with each other bypassing through the aperture array 61 and travel downward, incident tothe hole of the aperture 52.

The aperture 52 is a plate-shaped member provided with a center holethrough which the electron beams EBmn pass. The aperture 52 is disposedin the vicinity of a convergence point (crossover point) of the electronbeams EBmn passing through the lens 42. As each electron beam EBmnpasses through the hole of the aperture 52, each electron beam EBmn isshaped in a shot shape. In addition, when the electron beams EBmn aredeflected by the blanker BK of the aperture array 61, the electron beamsEBmn are blanked by the aperture 52.

The deflector 62 is disposed under the aperture 52. The deflector 62 hasa plurality of pairs of electrodes arranged to face each other. Thedeflector 62 deflects the electron beams EBmn passing through theaperture 52 depending on a voltage applied to the electrodes. In thisembodiment, for simplicity purposes, only a single pair of electrodesseparated by a predetermined distance in the X-axis direction areillustrated in the drawings, the deflector 62 may deflect the electronbeams EBmn in the X-axis and Y-axis directions.

The lens 43 is an annular electromagnetic lens disposed to surround thedeflector 62. The lens 43 focuses the electron beams EBmn on a desiredposition of the specimen 120 placed on the stage 70 in cooperation withthe deflector 62.

The stage 70 is disposed inside the writing chamber 80 a. The stage 70is a stage capable of moving at least within the horizontal plane whilethe specimen 120 to be patterned is maintained nearly horizontally. Onthe upper surface of the stage 70, a mirror Mx whose longitudinaldirection is set to the Y-axis direction and a mirror My whoselongitudinal direction is set to the X-axis direction are provided. Aposition within the horizontal plane of the stage 70 is detected withrespect to the mirrors Mx and My.

The control system 100 is a system for controlling the irradiator 20 andthe stage 70. The control system 100 has a controller 101, a powersource 102, a lens driver 103, a BAA controller 104, a deflectionamplifier 105, and a stage driver 106.

FIG. 7 is a block diagram illustrating the controller 101. Asillustrated in FIG. 7, the controller 101 is a computer having a centralprocessing unit (CPU) 101 a, a main memory 101 b, an auxiliary memory101 c, an input unit 101 d, a display 101 e, an interface 101 f, and asystem bus 101 g used to connect these elements.

The CPU 101 a reads a program stored in the auxiliary memory 101 c andexecutes the program. In addition, the CPU 101 a integrally controls theelements of the control system 100 on the basis of the program.

The main memory 101 b has a volatile memory such as a random accessmemory (RAM). The main memory 101 b is used as a work area of the CPU101 a.

The auxiliary memory 101 c has a non-volatile memory such as a read-onlymemory (ROM), a magnetic disc, and a semiconductor memory. The auxiliarymemory 101 c stores a program executed by the CPU 101 a, image data PDTrepresenting a pattern to be drawn on the specimen 120, variousparameters, and the like.

The input unit 101 d has a pointing device such as a keyboard or amouse. A user's instruction is input through the input unit 101 d and isnotified to the CPU 101 a via the system bus 101 g.

The display 10 le has a display device such as a liquid crystal display(LCD). The display 101 e displays information regarding a status of theelectron beam lithography apparatus 10, a lithographic pattern PDT, andthe like.

The interface 101 f has a LAN interface, a serial interface, a parallelinterface, an analog interface, and the like. The power source 102, thelens driver 103, the BAA controller 104, the deflection amplifier 105,and the stage driver 106 are connected to the controller 101 through theinterface 101 f.

The controller 101 configured as described above integrally controls thepower source 102, the lens driver 103, the BAA controller 104, thedeflection amplifier 105, and the stage driver 106.

Returning to FIG. 1, the power source 102 applies a voltage to theelectron gun 30 in response to an instruction from the controller 101.As a result, the electron beam EB is ejected from the electron gun 30downward.

The lens driver 103 controls (refractive) power of the lens 41 for theelectron beam EB on the basis of the instruction from the controller 101such that the electron beam EB spreading downward is shaped into anelectron beam traveling in parallel to the vertical direction. Inaddition, the lens driver 103 controls power of the lens 42 such thatthe electron beams EBmn are converged into the center of the aperture52. Furthermore, the lens driver 103 controls power of the lens 43 suchthat the electron beams EBmn are focused on the upper surface of thespecimen 120.

Similar to the controller 101, the BAA controller 104 is a computerhaving a CPU. The converters 621 to 628 are connected to the BAAcontroller 104 as illustrated in FIG. 8. The BAA controller 104 createsserial data S1 to S8 on the basis of the image data PDT transmitted fromthe controller 101. In addition, the BAA controller 104 outputs theserial data S1 to S8 to the converters 621 to 628. The operation of theBAA controller 104 will be described below.

Returning to FIG. 1, the deflection amplifier 105 generates a voltagesignal on the basis of an instruction from the controller 101 andoutputs the voltage signal to the electrodes of the deflector 62. As aresult, a voltage difference is generated between the electrodes of thedeflector 62. The electron beams EBmn passing through the deflector 62are deflected as much as the voltage difference.

The stage driver 106 measures positions of the mirrors Mx and My of thestage 70 using a laser sensor (not shown) and the like and detects aposition of the stage 70 on the basis of the measurement result. Inaddition, the stage driver 106 drives the stage 70 on the basis of aninstruction from the controller 101 to move or position the specimen120.

<Operation of Apparatus>

In the electron beam lithography apparatus 10 described above, thecontroller 101 integrally controls the power source 102, the lens driver103, the BAA controller 104, the deflection amplifier 105, and the stagedriver 106. For example, if the pattern is drawn on the specimen 120using the electron beam lithography apparatus 10, the CPU 101 a of thecontroller 101 drives the stage 70 where the specimen 120 is placed inorder to position the specimen 120 under the irradiator 20.

The CPU 101 a drives the power source 102 to apply a voltage to theelectron gun 30. As a result, the electron beam EB is ejected from theelectron gun 30.

As the electron beam EB is ejected from the electron gun 30, the CPU 101a controls the lens 41 using the lens driver 103 to shape the electronbeam EB spreading downward so as to be parallel to the vertical axis.

The electron beam EB shaped by the lens 41 travels downward and passesthrough the aperture 51. As a result, the electron beam EB is branchedinto a plurality of (sixty four) electron beams EBmn. The electron beamsEBmn pass through the blankers BKmn of the aperture array 61 and travelthrough holes HHmn of the substrate 610 included in the aperture array61.

The CPU 101 a controls the lens 42 using the lens driver 103 such thateach of the electron beams EBmn passing through the aperture array 61 isconverged in the vicinity of the hole of the aperture 52.

As each of the electron beams EBmn passes through the hole of theaperture 52, an outer diameter and a shape of the shot are shaped. Theelectron beams EBmn passing through the aperture 52 are incident to thelens 43.

The CPU 101 a controls the lens 43 using the lens driver 103 such thatthe electron beams EBmn incident to the lens 43 are focused on thesurface of the specimen 120 held by the stage 70. In addition, the CPU101 a controls an incident position of the electron beam EBmn to thespecimen 120 by deflecting the electron beams EBmn in the X-axis orY-axis direction using the deflection amplifier 105.

In addition to the aforementioned operation, the CPU 101 a outputs theimage data PDT to the BAA controller 104. The ON/OFF control of theelectron beams EBmn incident to the specimen 120 is performed on thebasis of the image data PDT.

FIG. 9 is a diagram illustrating a unit pattern PA drawn on the basis ofthe image data PDT by way of example. The unit pattern PA includes sixtyfour marks Mmn drawn by the sixty four electron beams EBmn. The electronbeam lithography apparatus 10 draws a circuit pattern CPA including theunit pattern PA on the specimen 120 by sequentially drawing the unitpattern PA on the upper surface of the specimen 120 as indicated by thearrow in FIG. 10.

FIG. 11 is a schematic diagram illustrating the image data PDT as anexample. As illustrated in FIG. 11, the image data PDT includes unitdata D1 to D64 representing doses of the electron beams for drawing thesixty four marks Mmn. For example, the image data PDT is bitmap data inwhich the unit data D1 to D64 are arranged in an eight-row andeight-column matrix shape in the Dy-axis and Dx-axis directions. Theimage data PDT is stored in the auxiliary memory 101 c of the controller101 in advance. In addition, when the drawing on the specimen 120starts, the image data is output to the BAA controller 104.

The BAA controller 104 creates the serial data S1 to S8 on the basis ofthe image data PDT.

Specifically, the BAA controller 104 divides the unit data D1 to D64 ofthe image data PDT into eight data groups G1 to G8 as illustrated inFIG. 12. As shown in FIGS. 4, 6, and 12, the unit data of the data groupG1 correspond to the blankers BK11 to BK14 and BK21 to BK24. The unitdata of the data group G2 correspond to the blankers BK31 to BK34 andBK41 to BK44. The unit data of the data group G3 correspond to theblankers BK51 to BK54 and BK61 to BK64. The unit data of the data groupG4 correspond to the blankers BK71 to BK74 and BK81 to BK84. The unitdata of the data group G5 correspond to the blankers BK15 to BK18 andBK25 to BK28. The unit data of the data group G6 correspond to theblankers BK35 to BK38 and BK45 to BK48. The unit data of the data groupG7 correspond to the blankers BK55 to BK58 and BK65 to BK68. The unitdata of the data group G8 correspond to the blankers BK75 to BK78 andBK85 to BK88.

The BAA controller 104 divides the unit data of the data groups G1 to G8into blocks of the unit data whose number is equivalent to the number ofdata output from the converters 621 to 628 in parallel. As illustratedin FIG. 6, the converters 621 to 628 has four output lines L1 to L4. TheBAA controller 104 divides the unit data of each data group G1 to G8into four-row and four-column blocks of the unit data.

For example, as illustrated in FIG. 13, the BAA controller 104 dividesthe unit data of the data group G1 into a block B11 including the unitdata D1, D2, D9, and D10 and a block B12 including the unit data D17,D18, D25, and D26.

Similarly, the BAA controller 104 divides the unit data of each datagroup G2 to G8 into blocks B21 to B81 and blocks B22 to B82.

The block B21 of the data group G2 includes the unit data D3, D4, D11,and D12, and the block B22 includes the unit data D19, D20, D27, andD28. The block B31 of the data group G3 includes the unit data D5, D6,D13, and D14, and the block B32 includes the unit data D21, D22, D29,and D30. The block B41 of the data group G4 includes the unit data D7,D8, D15, and D16, and the block B42 includes the unit data D23, D24,D31, and D32. The block B51 of the data group G5 includes the unit dataD33, D34, D41, and D42, and the block B52 includes the unit data D49,D50, D57, and D58. The block B61 of the data group G6 includes the unitdata D35, D36, D43, and D44, and the block B62 includes the unit dataD51, D52, D59, and D60. The block B71 of the data group G7 includes theunit data D37, D38, D45, and D46, and the block B72 includes the unitdata D53, D54, D61, and D62. The block BS81 of the data group G8includes the unit data D39, D40, D47, and D48, and the block B82includes the unit data D55, D56, D63, and D64.

The BAA controller 104 sorts the unit data of the block B11 of the datagroup G1 and the unit data of the block B12 of the data group G1according to a predetermined rule. FIG. 14 is a schematic diagramillustrating a process of generating the serial data S1 from the datagroup G1. The BAA controller 104 divides the data group G1 into blocksB11 and B12 as illustrated in FIG. 14 and sorts the unit data of theblocks B11 and B12 according to the sorting rule of FIG. 14.

The sorting rule is defined on the basis of a relationship between theconverter 621 where the unit data D1, D2, D9, D10, D17, D18, D25, andD26 of the block B11 are output and the blankers BK11 to BK14 and BK21to BK24. For example, as illustrated by FIG. 6, if the converter 621firstly outputs the unit data D10 to the output line L1 for the blankerBK22, secondly outputs the unit data D9 to the output line L2 for theblanker BK12, thirdly outputs the unit data D2 to the output line L3 forthe blanker BK21, and fourthly outputs the unit data D1 to the outputline L4 for the blanker BK11, the BAA controller 104 creates serial dataS11 [D10, D9, D2, D1] having the unit data D10 as a head by sorting theunit data D1, D2, D9, and D10.

Similarly, the BAA controller 104 creates serial data S12 [D26, D25,D18, D17] having the unit data D26 as a head by sorting the unit dataD17, D18, D25, and D26 of the block B12.

As illustrated by FIG. 6, in the output lines L1 to L4 of the converter621, the blankers BK13, BK23, BK14, and BK24 corresponding to the unitdata D17, D18, D25, and D26 are placed in the downstream of the blankersBK11, BK21, BK12, and BK22 corresponding to the unit data D1, D2, D9,and D10. In this regard, the BAA controller 104 exchanges the sequencesof the serial data S12 and S11 with each other and combines theexchanged sequences as illustrated in FIG. 14 so as to create serialdata S1 [D26, D25, D18, D17, D10, D9, D2, D1] having the unit data D26as a head. In this manner, the image data PDT is converted to createserial data S1 suitable for the format of the converter 621. The BAAcontroller 104 outputs the serial data S1 to the converter 621.

As the serial data S is output to the converter 621, unit data of theserial data S1 are sequentially output from the output lines L1 to L4.As the unit data D26, D25, D18, and D17 of the serial data S1 aresequentially output, the unit data D26, D25, D18, and D17 are stored inthe shift register SR1 of the output lines L1 to L4 as illustrated inFIG. 15. Subsequently, when the unit data D10, D9, D2, and D1 aresequentially output, the unit data D26, D25, D18, and D17 are sent tothe shift register SR2 of the output lines L1 to L4 and are storedtherein as illustrated in FIG. 16. In addition, the unit data D10, D9,D2, and D1 are stored in the shift register SR1 of the output lines L1to L4.

If the unit data D1, D9, D17, D25, D2, D10, D18, and D26 are stored inboth the shift registers SR1 and SR2 of the output lines L1 to L4, eachof the unit data is output to the blankers BK11, BK12, BK13, BK14, BK21,BK22, BK23, and BK24 through the buffer BF. As a result, a dose of theelectron beams EBmn passing through the holes HH11, HH12, HH13, HH14,HH21, HH22, HH23, and HH24 is controlled on the basis of the values ofthe unit data. Consequently, as illustrated in FIG. 17, the marks M11 toM14 and M21 to M24 of the unit pattern PA are drawn with a predetermineddose.

The BAA controller 104 also creates serial data S2 to S4 from the unitdata of the data groups G2 to G4 and outputs them to the converters 622,623, and 624. As a result, the marks Mm1 to Mm4 are drawn in the lefthalf area of the unit pattern PA of FIG. 9.

FIG. 18 is a schematic diagram illustrating serial data obtained byarranging the unit data D1 to D32 on the basis of the arrangement rankof the image data PDT and serial data obtained by arranging the unitdata D1 to D32 on the basis of the sorting rule. Through the processdescribed above, the unit data D1 to D32 are converted from the serialdata having the unit data D1 as a head and the unit data D32 as a tailinto the serial data S11, S12, S21, S22, S31, S32, S41, and S42. Inaddition, the converted serial data are sequentially output one by oneto the lines L1 to L4 of the converters 621 to 624 of FIG. 6. As aresult, the serial data S1 to S4 are output to the converters 621 to624, respectively.

Similarly, the BAA controller 104 sorts the unit data of the block B51of the data group G5 and the unit data of the block B52 of the datagroup G5 on the basis of a predetermined rule. FIG. 19 is a schematicdiagram illustrating a process of creating serial data S5 from the datagroup G5. The BAA controller 104 divides the data group G5 into theblocks B51 and B52 as illustrated in FIG. 19. Then, the BAA controller104 sorts the unit data of the blocks B51 and B52 on the basis of thesorting rule illustrated in FIG. 19.

The sorting rule is defined by a relationship between the converter 625and the blankers BK15 to BK18 and BK25 to BK28. The unit data D33, D34,D41, D42, D49, D50, D57, and D58 of the block B51 are output to theconverter 625. The BAA controller 104 creates the serial data S51 [D34,D33, D42, D41] having the unit data D34 as a head by sorting the unitdata D33, D34, D41, and D42.

Similarly, the BAA controller 104 creates serial data S52 [D50, D49,D58, D57] having the unit data D50 as a head by sorting the unit dataD49, D50, D57, and D58 of the block B52.

As illustrated by FIG. 6, in the output lines L1 to L4 of the converter625, the blankers BK15, BK25, BK16, and BK26 corresponding to the unitdata D33, D34, D41, and D42 are placed in the downstream of the blankersBK17, BK27, BK18, and BK28 corresponding to the unit data D49, D50, D57,and D58. In this case, the BAA controller 104 combines the serial dataS51 and S52 without exchanging their sequences as illustrated in FIG. 19to create serial data S5 [D34, D33, D42, D41, D50, D49, D58, D57] havingthe unit data D34 as a head. In this manner, serial data S5 suitable forthe format of the converter 625 is created by converting the image dataPDT. The BAA controller 104 outputs the serial data S5 to the converter625.

When the serial data S5 is output to the converter 625, the unit data ofthe serial data S5 are sequentially output from the output lines L1 toL4. When the unit data D34, D33, D42, and D41 of the serial data S5 aresequentially output, the unit data D34, D33, D42, and D41 are stored inthe shift register SR1 of the output lines L1 to L4 as illustrated inFIG. 20. Subsequently, When the unit data D50, D49, D58, and D57 aresequentially output, the unit data D34, D33, D42, and D41 are sent tothe shift register SR2 of the output lines L1 to L4 and are storedtherein as illustrated in FIG. 21. In addition, the unit data D50, D49,D58, and D57 are stored in the shift register SR1 of the output lines L1to L4.

If the unit data D33, D41, D49, D57, D34, D42, D50, and D58 are storedin both the shift registers SR1 and SR2 of the output lines L1 to L4,the unit data are output to the blankers BK15, BK16, BK17, BK18, BK25,BK26, BK27, and BK28, respectively, through the buffer BF. As a result,a dose of the electron beams EBmn passing through the holes HH15, HH16,HH17, HH18, HH25, HH26, HH27, and HH28 is controlled on the basis of thevalue of the unit data. Consequently, as illustrated in FIG. 22, themarks M15 to M18 and M25 to M28 of the unit pattern PA are drawn with apredetermined dose.

The BAA controller 104 also creates the serial data S6 to S8 from theunit data of the data groups G6 to G8 and outputs the serial data S6 toS8 to the converters 626, 627, and 628. As a result, the marks Mm5 toMm8 are drawn in the right half area of the unit pattern PA of FIG. 9,so that the drawing of the unit pattern PA is completed.

FIG. 23 is a schematic diagram illustrating serial data obtained byarranging the unit data D33 to D64 on the basis of the arrangement rankof the image data PDT and serial data obtained by arranging the unitdata D33 to D64 on the basis of a sorting rule. In the process describedabove, the unit data D33 to D64 are converted from the serial datahaving the unit data D33 as a head and the unit data D64 as a tail intothe serial data S51, S52, S61, S62, S71, S72, S81, and S82. In addition,the converted serial data are sequentially output one by one to thelines L1 to L4 of the converters 625 to 628 of FIG. 6. As a result, theserial data S5 to S8 are output to the converters 625 to 628,respectively.

The electron beam lithography apparatus 10 consecutively draws the unitpattern PA on the upper surface of the specimen 120 as illustrated inFIG. 10 on the basis of the aforementioned method to finally obtain thecircuit pattern CPA.

In the electron beam lithography apparatus 10, the unit data of theimage data PDT are sorted as described above. When the unit data aresorted, a sorting error may occur, for example, if the number of theunit data of the image data PDT is too large. In this regard, in theelectron beam lithography apparatus 10, a sorting error is diagnosedusing a checksum. An error diagnosis process for diagnosing a sortingerror will be described below with reference to FIG. 24.

<Diagnosis Process>

FIG. 24 is a flowchart illustrating an error diagnosis process. A seriesof processes of FIG. 24 are executed by the BAA controller 104.

The BAA controller 104 calculates a checksum for each arrangement rankof the unit data of each block of the data groups G1 to G4 in the leftarea of the image data PDT (step S101).

As shown in FIGS. 25 and 26, the BAA controller 104 calculates achecksum CS1 by summing the values of the first unit data D1, D3, D5,D7, D17, D19, D21, and D23 of each block B11, B21, B31, B41, B12, B22,B32, and B42. Similarly, the BAA controller 104 calculates checksums CS2to CS4 by summing the second to fourth unit data of each block B11, B21,B31, B41, B12, B22, B32, and B42.

The following checksums CS1 to CS4 obtained in this manner are based onthe arrangement ranks of the unit data in the image data PDT. If thechecksums CS1 to CS4 are calculated as described below, the number ofthe checksums becomes equal to the number of the unit data in the block.For this reason, a data area for storing the checksums can be reduced,compared to a case where the checksum is calculated for each rank (firstto eight ranks) of the data group.CS1=D1+D3+D5+D7+D17+D19+D21+D23CS2=D2+D4+D6+D8+D18+D20+D22+D24CS3=D9+D11+D13+D15+D25+D27+D29+D31CS4=D10+D12+D14+D16+D26+D28+D30+D32

The BAA controller 104 calculates checksums of each rank on the unitdata sorting rule for each block of the data groups G1 to G4 in the leftarea of the image data PDT (step S102).

As recognized from FIGS. 27 and 28, the BAA controller 104 calculates achecksum ACS1 by summing the values of the first unit data D10, D12,D14, D16, D26, D28, D30, and D32 on the sorting rule of each block B11,B21, B31, B41, B12, B22, B32, and B42. Similarly, the BAA controller 104calculates checksums ACS2 to ACS4 by summing the second to fourth unitdata of each block B11, B21, B31, B41, B12, B22, B32, and B42.

The checksums ACS1 to ACS4 obtained in this manner are based on thearrangement rank of the sorting rule.ACS1=D26+D28+D30+D32+D10+D12+D14+D16ACS2=D25+D27+D29+D31+D9+D11+D13+D15ACS3=D18+D20+D22+D24+D2+D4+D6+D8ACS4=D17+D19+D21+D23+D1+D3+D5+D7

The BAA controller 104 calculates checksums of each arrangement rank ofthe unit data for each block of the data groups G5 to G8 in the rightarea of the image data PDT of FIG. 13 (step S103). The followingresultant checksums CS5 to CS8 are based on the arrangement rank of theunit data in the image data PDT.CS5=D33+D35+D37+D39+D49+D51+D53+D55CS6=D34+D36+D38+D40+D50+D52+D54+D56CS7=D41+D43+D45+D47+D57+D59+D61+D63CS8=D42+D44+D46+D48+D58+D60+D62+D64

As shown in FIG. 27, the BAA controller 104 calculates checksums of eachrank on the unit data sorting rule for each block of the data groups G5to G8 in the right area of the image data PDT (step S104). The followingresultant checksums ACS5 to ACS8 are based on the arrangement rank onthe sorting rule.ACS5=D34+D36+D38+D40+D50+D52+D54+D56ACS6=D33+D35+D37+D39+D49+D51+D53+D55ACS7=D42+D44+D46+D48+D58+D60+D62+D64ACS8=D41+D43+D45+D47+D57+D59+D61+D63

The BAA controller 104 compares the checksums CS1 to CS8 and thechecksums ACS1 to ACS8 (step S105).

As recognized from FIG. 29, for the data group G1 to G4, the arrangementranks 1, 2, 3, and 4 correspond to the sorting rule ranks 4, 3, 2, and1. For this reason, it is natural that the unit data of the checksum CS1matches the unit data of the checksum ACS4, and the checksum CS1 isequal to the checksum ACS4 as illustrated in FIG. 31.

Similarly, it is natural that the checksums CS2, CS3, and CS4 are equalto the checksums ACS3, ACS2, and ACS1, respectively.

As recognized from FIG. 30, for the data groups G5 to G8, thearrangement ranks 1, 2, 3, and 4 correspond to the sorting rule ranks 2,1, 4, and 3. For this reason, it is natural that the unit data of thechecksum CS5 matches the unit data of the checksum ACS6, and thechecksum CS5 is equal to the checksum ACS6 as illustrated in FIG. 31.

Similarly, it is natural that the checksums CS6, CS7, and CS8 are equalto the checksums ACS5, ACS8, and ACS7, respectively.

Here, the BAA controller 104 compares the corresponding checksums witheach other as illustrated in FIG. 31.

The BAA controller 104 determines whether or not an error occurs inconversion of the image data PDT on the basis of a result of thechecksum comparison (step S106). The BAA controller 104 determines thatthere is an error in conversion of the image data PDT if there is adifference between the corresponding checksums (YES in step S106). Forexample, if the checksum CS11 has a value of “X,” and the checksum ACS14has a value of “Y” different from “X,” it is determined that there is anerror in conversion of the image data PDT.

Meanwhile, if the corresponding checksums have an identical value, theBAA controller 104 determines that there is no error in conversion ofthe image data PDT (NO in step S106). For example, if the checksum CS11has a value of “Z,” and the checksum ACS14 also has a value of “Z,” itis determined that there is no error in conversion of the image dataPDT.

If there is an error in conversion of the image data PDT, the BAAcontroller 104 notifies a result of the checksum comparison, forexample, to the controller 101 (step S107). As a result, for example,patterning on the specimen 120 is interrupted.

FIG. 32 is a diagram conceptually illustrating the original image dataPDT and image data APDT equivalent to the serial data obtained byconverting the original image data PDT. As shown in FIG. 32, in theelectron beam lithography apparatus 10, the data are output while thepositions of the blocks B11, B21, B31, and B41 in the original imagedata PDT are exchanged with the positions of the blocks B12, B22, B32,and B42.

In this regard, in order to diagnose an error generated by the blockexchange, the BAA controller 104 calculates a checksum based on theoriginal image data PDT (step S108).

Specifically, the BAA controller 104 calculates a checksum CSB1 bysumming the unit data of the blocks B11, B21, B31, and B41 of the imagedata PDT and calculates a checksum CSB2 by summing the unit data of theblocks B12, B22, B32, and B42. The checksum CSB1 can be calculated onthe basis of the following Equation (1). In addition, the checksum CSB2can be calculated on the basis of the following Equation (2).CSB1=D1+D2+D9+D10+D3+D4+ . . . +D16  (1)CSB2=D17+D18+D25+D26+D19+D20+ . . . +D32  (2)

The BAA controller 104 calculates a checksum based on the image dataAPDT equivalent to the serial data (step S109).

Specifically, the BAA controller 104 calculates the checksum ACSB1 bysumming the unit data of the blocks B11, B21, B31, and B41 of the imagedata APDT and calculates the ACSB2 by summing the unit data of theblocks B12, B22, B32, and B42. The checksum ACSB1 can be calculated onthe basis of the following Equation (3). The checksum ACSB2 can becalculated on the basis of the following Equation (4).ACSB1=D10+D9+D2+D1+D12+D11+ . . . +D7  (3)ACSB2=D26+D25+D18+D17+D28+D27+ . . . +D23  (4)

The BAA controller 104 compares the checksums CSB1 and CSB2 and thechecksums ACSB1 and ACSB2 (step S110).

As shown in FIG. 32, it is natural that the checksum CSB1 representing asum of the unit data of the blocks B11, B21, B31, and B41 of the imagedata PDT is equal to the checksum ACSB1 representing a sum of the unitdata of the blocks B11, B21, B31, and B41 of the image data APDT.Similarly, it is natural that the checksum CSB2 representing a sum ofthe unit data of the blocks B12, B22, B32, and B42 of the image data PDTis equal to the checksum ACSB2 representing a sum of the unit data ofthe blocks B12, B22, B32, and B42 of the image data APDT.

Then, the BAA controller 104 determines whether or not an error isgenerated from the block exchange process on the basis of a result ofthe checksum comparison (step S111). If there is a difference betweenthe corresponding checksums, the BAA controller 104 determines thatthere is an error in conversion of the image data PDT (YES in stepS111). For example, if the checksum CSB1 has a value of “X,” and thechecksum ACSB1 has a value of “Y” different from “X,” it is determinedthat there is an error in the block exchange process.

Meanwhile, if the values of the corresponding checksums are equal toeach other, the BAA controller 104 determines that there is no error inthe block exchange process (NO in step S111). For example, if thechecksum CSB1 has a value of “Z,” and the checksum ACSB1 has theidentical value of “Z,” it is determined that there is no error in theblock exchange process.

If there is an error in the block exchange process, the BAA controller104 notifies the controller 101 of a result of the checksum comparison,for example, (step S112). As a result, for example, pattering on thespecimen 120 is interrupted.

If the process of step S112 is terminated, or it is determined thatthere is no error in step S111, the BAA controller 104 terminates theerror diagnosis process.

As described above, according to this embodiment, the checksum iscalculated for each rank of the unit data contained in the blocks of theimage data PDT (steps S101 to S104). For this reason, it is possible todiagnose an error generated in parallel/serial conversion of the imagedata PDT by comparing the checksums (step S105). As a result, it ispossible to detect a conversion error with high accuracy and improve apatterning resolution.

According to this embodiment, when the image data PDT is converted intothe image data APDT, the checksum is calculated for each group of theexchanged blocks as illustrated in FIG. 32 (steps S108 and S109). Forthis reason, by comparing the checksums (step S110), it is possible todiagnose an error generated in the block exchange process. As a result,it is possible to detect a conversion error with high accuracy andimprove a patterning resolution.

As described above, according to this embodiment, a diagnosis can beperformed for each particular process such as parallel/serial conversionof the image data PDT or the block exchange process. Therefore, it ispossible to easily specify when a patterning error is generated duringthe processing and reduce a downtime of the system.

While embodiments according to the present disclosure have beendescribed, they are not intended to limit the scope of the presentdisclosure. For example, although a dose of the electron beams EBmn isdetermined on the basis of the values of the unit data D1 to D64,various other methods may also be employed to control the dose of theelectron beams EBmn. For example, the dose of the electron beams EBmnmay be controlled in an ON/OFF manner on the basis of the values of theunit data D1 to D64. In addition, the unit data D1 to D64 may have a bitlength of several bits to several tens of bits, and the electron beamirradiation time may be controlled depending on the bit value. As aresult, marks Mmn having various gradations can be formed. An example ofthe dose control will be described below.

<Dose Control>

FIG. 33 is a schematic diagram illustrating unit data Di (where “i”=1 to64). The unit data Di (where “i”=1 to 64) are, for example, 8-bit data,and first to eighth bit data are set to Xi(1) to Xi(8), respectively.The bit data Xi(1) to Xi(8) has a value of “1” or “0.” The irradiationtime of the electron beam EBmn is allocated to the bit data Xi(1) toXi(8). In the electron beam lithography apparatus 10, for example, theirradiation times 6 ns, 12 ns, 24 ns, 48 ns, 96 ns, 192 ns, 384 ns, and768 ns are allocated to the bit data Xi(1) to Xi(8), respectively, asillustrated in FIG. 33. For this reason, the irradiation time IT (ns)shown in the unit data Di can be represented as the following Equation(5). For example, if the unit data Di (Xi(1) to Xi(8)) is set to[10100000], the irradiation time IT becomes 30 ns (=6·1+24·1).IT=6Xi(1)+12Xi(2)+24Xi(3)+48Xi(4)+96Xi(5)+192Xi(6)+384Xi(7)+768Xi(8)  (5)

The BAA controller 104 sorts the bit data of the unit data Di on thebasis of a predetermined rule. For example, if the ON/OFF control of theelectron beams EBmn is performed sequentially from the first bit of thebit data Xi(1) to the eighth bit of the bit data Xi(8), the ON/OFFswitching control of the electron beam EBmn for every short intervalsuch as 6 ns, 12 ns, or 24 ns may be necessary in the first half. Inthis regard, the BAA controller 104 performs the exchange process of thebit data Xi(1) to Xi(8) of the unit data Di on the basis of apredetermined rule.

For example, the BAA controller 104 combines the bit data Xi1representing “6 ns” and the bit data Xi8 representing “768 ns” asillustrated in FIG. 34. Similarly, the bit data Xi(2) representing “12ns” and the bit data Xi(7) representing “384 ns” are combined. The bitdata Xi(3) representing “24 ns” and the bit data Xi(6) representing “192ns” are combined. The bit data Xi(4) representing “48 ns” and the bitdata Xi(5) representing “96 ns” are combined. As a result, the unit dataDi is converted into unit data ADi [Xi(4), Xi(5), Xi(3), Xi(6), Xi(2),Xi(7), Xi(1), and Xi(8)].

From the converters 621 to 628, the data DXi(4) to DXi(8) correspondingto the first bit of the bit data Xi(4) to the eighth bit of the bit dataXi(8) of the unit data ADi are sequentially output. Note that the dataDXi(1) to DXi(8) are data for turning on the electron beam EBmn only forthe irradiation time allocated to the bit data Xi(l) to Xi(8).

For example, the converter 621 outputs data DX26(4), DX25(4), DX18(4),and DX17(4) corresponding to the first bits X26(4), X25(4), X18(4), andX17(4) of the unit data D26, D25, D18, and D17, respectively, to theoutput lines L1 to L4. Then, the converter 621 outputs data DX10(4),DX9(4), DX2(4), and DX1(4) corresponding to the first bits X10(4),X9(4), X2(4), and X1(4) of the unit data D10, D9, D2, and D1,respectively, to the output lines L1 to L4. Similarly, the converter 621repeats the above described operation for the second and subsequent bitsof the unit data D26, D25, D18, D17, D10, D9, D2, and D1.

If the converters 621 to 628 repeat the above described operation foreach bit data of the unit data Di, a mark Mmn having a predeterminedgradation is formed.

<Diagnosis Process>

The BAA controller 104 calculates a checksum before and after the bitdata exchange process of the unit data Di. For example, the value VDi ofthe unit data Di itself can be expressed as the following Equation (6).Therefore, the checksum CSD before the sorting of the unit data Di canbe obtained using the following Equation (7).VDi=2⁷ Xi(8)+2⁶ Xi(7)+2⁵ Xi(6)+2⁴ Xi(5)+2³ Xi(4)+2² Xi(3)+2¹ Xi(2)+2⁰Xi(1)  (6)

$\begin{matrix}{{CSD} = {{{\left( {{X\; 1(8)} + {X\; 2(8)} + {\ldots\mspace{14mu} X\; 64(8)}} \right) \times 2^{7}} + {\left( {{X\; 1(7)} + {X\; 2(7)} + {\ldots\mspace{14mu} X\; 64(7)}} \right) \times 2^{6}} + {\left( {{X\; 1(6)} + {X\; 2(6)} + {\ldots\mspace{14mu} X\; 64(6)}} \right) \times 2^{5}} + {\left( {{X\; 1(5)} + {X\; 2(5)} + {\ldots\mspace{14mu} X\; 64(5)}} \right) \times 2^{4}} + {\left( {{X\; 1(4)} + {X\; 2(4)} + {{\ldots X}\; 64(4)}} \right) \times 2^{3}} + {\left( {{X\; 1(3)} + {X\; 2(3)} + {\ldots\mspace{14mu} X\; 64(3)}} \right) \times 2^{2}} + {\left( {{X\; 1(2)} + {X\; 2(2)} + {\ldots\mspace{14mu} X\; 64(2)}} \right) \times 2^{1}} + {\left( {{X\; 1(1)} + {X\; 2(1)} + {\ldots\mspace{14mu} X\; 64(1)}} \right) \times 2^{0}}} = {{k\; 8 \times 2^{7}} + {k\; 7 \times 2^{6}} + {k\; 6 \times 2^{5}} + {k\; 5 \times 2^{4}} + {k\; 4 \times 2^{3}} + {k\; 3 \times 2^{2}} + {k\; 2 \times 2^{1}} + {k\; 1 \times 2^{0}}}}} & (7)\end{matrix}$

The BAA controller 104 calculates the checksum ACSD for the unit dataADi [Xi(8), Xi(1), Xi(7), Xi(2), Xi(6), Xi(3), Xi(5), and Xi(4)] createdby exchanging the bit data Xi(1) to Xi(8) of the unit data Di.

Specifically, the BAA controller 104 first calculates a sum Σ(j) of thebit data of the (j)th rank (j=1 to 8) from the bit data Xi(1) to Xi(64)of the sixty four unit data ADi on the basis of the following Equations(8) to (15).Σ(1)=X1(4)+X2(4)+ . . . +X64(4)  (8)Σ(2)=X1(5)+X2(5)+ . . . +X64(5)  (9)Σ(3)=X1(3)+X2(3)+ . . . +X64(3)  (10)Σ(4)=X1(6)+X2(6)+ . . . +X64(6)  (11)Σ(5)=X1(2)+X2(2)+ . . . +X64(2)  (12)Σ(6)=X1(7)+X2(7)+ . . . +X64(7)  (14)Σ(7)=X1(1)+X2(1)+ . . . +X64(1)  (13)Σ(8)=X1(8)+X2(8)+ . . . +X64(8)  (15)

As recognized by comparing Equations (8) to (15) with Equation (7), ifthe exchange process of the bit data Xi(1) to Xi(8) is successful, thesum Σ(1) is equal to a coefficient “k4.” Similarly, the sum Σ(2) isequal to the coefficient “k5.” The sum Σ(3) is equal to the coefficient“k3.” The sum Σ(4) is equal to the coefficient “k6.” The sum Σ(5) isequal to the coefficient “k2.” The sum Σ(6) is equal to the coefficient“k7.” The sum Σ(7) is equal to the coefficient “k1.” The sum Σ(8) isequal to the coefficient “k8.”

In this regard, the BAA controller 104 calculates the checksum ACSDusing the following Equation (16).ACSD=Σ(8)×2⁷+Σ(7)×2⁶+Σ(6)×2⁵+Σ(5)×2⁴+Σ(4)×2³+Σ(3)×2²+Σ(2)×2¹+Σ(1)×2⁰  (16)

The BAA controller 104 compares the checksums CSD and ACSD calculated asdescribed above. If both the checksums CSD and ACSD are equal to eachother, the BAA controller 104 determines that the exchange process ofthe bit data Xi(1) to Xi(8) is successful. Otherwise, if the checksumsCSD and ACSD have different values as a result of comparison, the BAAcontroller 104 determines that there is an error in the exchange processof the bit data Xi(1) to Xi(8). In this case, the patterning on thespecimen 120 may be interrupted. As a result, it is possible to improvea patterning resolution.

While the embodiments of the present disclosure and their modificationshave been described, it would be appreciated that they are not intendedto limit the scope of the present disclosure. For example, although theelectron beam lithography apparatus draws a pattern using sixty fourelectron beams EBmn in the above described embodiments, the electronbeam lithography apparatus 10 may draw a pattern using sixty five ormore electron beams or sixty three or less electron beams without aparticular limitation.

In the embodiments described above, the unit data Di of the image dataPDT are divided into eight data groups G1 to G8 as illustrated in FIG.12. Alternatively, the unit data may be divided into seven or less datagroups or nine or more data groups depending on the number of unit dataof the image data PDT without a particular limitation.

In the embodiments described above, each of the converters 621 to 628outputs eight unit data as illustrated in FIG. 6. Alternatively, oneconverter may process nine or more unit data depending on aspecification of the converter without a particular limitation.

In the embodiments described above, the BAA controller 104 executes theerror diagnosis process of FIG. 24. Alternatively, the error diagnosisprocess may be executed by devices other than the BAA controller 104such as the controller 101 or any external device without a particularlimitation.

The functions of the BAA controller 104 according to each embodiment ofthe disclosure may be implemented in a dedicated hardware device or atypical computer system. The program executed by the BAA controller 104may be distributed while being stored in a computer-readable recordingmedium such as a flexible disk, a compact disc read-only memory(CD-ROM), a digital versatile disk (DVD). Alternatively, the program mayalso be installed in the BAA controller 104 via the Internet.

A part of or the entirety of the programs described above may beexecuted, for example, on a server, and information relating toexecution thereof may be received by the BAA controller 104 through acommunication network to execute the error diagnosis process.

While several embodiments according to the present invention have beendescribed, they are just for exemplary purposes and are not intended tolimit the scope of the invention. These novel embodiments may beembodied in various other forms, and various omissions, substitutions,or modifications may also be possible without departing from the scopeand spirit of the invention. Such various embodiments or modificationsshould be construed as being included in the scope and spirit of theinvention contained in the attached claims and equivalents thereof.

The invention claimed is:
 1. A method of diagnosing a conversion processfor converting a format of image data including unit data, wherein thedata is divided into blocks and units of each block are ranked,corresponding to charged particle beams into a format suitable for anaperture array, the aperture array having a plurality of controllersprovided to match a plurality of the charged particle beams to controlthe charged particle beams and a driver configured to drive thecontrollers, the method comprising: extracting the unit data having anidentical first rank based on an arrangement of the unit data in theimage data from the unit data of each block including a predeterminednumber of the unit data and calculating a first checksum of the unitdata having the same first rank; extracting the unit data having anidentical second rank after the conversion process from the unit data ofeach of the blocks and calculating a second checksum of the unit datahaving the same second rank; comparing the first and second checksums;and controlling the aperture array to control the plurality of chargedparticle beams according to a result of the comparing.
 2. The methodaccording to claim 1, wherein the driver is provided in each grouphaving a predetermined number of the controllers, further comprisingdividing the unit data into the blocks having the unit datacorresponding to an output of the driver.
 3. The method according toclaim 1, wherein the number of the unit data in each of the blocks isidentical one another between the blocks.
 4. The method according toclaim 1, further comprising: dividing each of the blocks into a firstblock and a second block; calculating a third checksum based on the unitdata included in the first block; calculating a fourth checksum based onthe unit data included in the second block; and comparing the thirdchecksum with the fourth checksum.
 5. The method according to claim 4,wherein a count of the unit data of the first block is equal to a countof the unit data of the second block.
 6. The method according to claim1, wherein the unit data include a plurality of bit data arranged basedon a third rank different from the first rank and the second rank, themethod further comprising: calculating a sum of values of the pluralityof unit data as a fifth checksum; summing the bit data of the unit datain the third rank: calculating a sixth checksum based on a result of thesumming; and comparing the fifth checksum with the sixth checksum. 7.The method according to claim 6, wherein a time for defining a dose ofthe charged particle beam is allocated to the bit data.
 8. The methodaccording to claim 6, wherein the bit data are paired, and the bit dataare arranged such that a difference of the dose defined by the pair ofthe bit data is minimized between the pair of bit data.
 9. A chargedparticle beam lithography apparatus comprising: an aperture array havinga plurality of controllers provided to match a plurality of chargedparticle beams to control the charged particle beams and a driverconfigured to drive the controllers; a converter configured to convert aformat of image data having unit data wherein the data is divided intoblocks and the units of each block are ranked, corresponding to thecharged particle beams into a format suitable for the aperture array; afirst calculator configured to extract the unit data having an identicalfirst rank based on the arrangement of the unit data of the image datafrom the unit data of each block having a predetermined number of theunit data and calculate a first checksum of the unit data having thesame first rank; a second calculator configured to extract the unit datahaving an identical second rank after the conversion of the converterfrom the unit data of each of the blocks and calculate a second checksumof the unit data having the same second rank; and a first comparatorconfigured to compare the first checksum with the second checksum. 10.The charged particle beam lithography apparatus according to claim 9,wherein the driver is provided in each group having a predeterminednumber of the controllers, and the unit data are divided into the blockshaving the unit data matching the output of the driver.
 11. The chargedparticle beam lithography apparatus according to claim 9, wherein eachof the blocks is divided into a first block and a second block, furthercomprising: a third calculator configured to calculate a third checksumbased on the unit data of the first block; a fourth calculatorconfigured to calculate a fourth checksum based on the unit data of thesecond block; and a second comparator configured to compare the thirdchecksum with the fourth checksum.
 12. The charged particle beamlithography apparatus according to claim 9, wherein the unit datainclude a plurality of bit data arranged based on a third rank differentfrom the first rank and the second rank, further comprising: a fifthcalculator configured to calculate a sum of values of the plurality ofunit data as a fifth checksum; a summer configured to sum the bit dataof the unit data of the third rank; a sixth calculator configured tocalculate a sixth checksum based on a result of the summing of thesummer; and a third comparator configured to compare the fifth checksumwith the sixth checksum.
 13. The charged particle beam lithographyapparatus according to claim 12, wherein a time for defining a dose ofthe charged particle beam is allocated to the bit data.
 14. The chargedparticle beam lithography apparatus according to claim 12, wherein thebit data are paired, and the bit data are arranged such that adifference of the dose defined by the pair of bit data is minimizedbetween the pair of bit data.
 15. A non-transitory computer readablerecording medium storing a program for diagnosing a conversion processfor converting a format of image data including unit data wherein thedata is divided into blocks and units of each block are ranked,corresponding to charged particle beams into a format suitable for anaperture array, the aperture array having a plurality of controllersprovided to match a plurality of the charged particle beams to controlthe charged particle beams, and a driver configured to drive thecontrollers, wherein the program causes a computer to execute:extracting the unit data having an identical first rank based on anarrangement of the unit data in the image data from the unit data ofeach block including a predetermined number of the unit data andcalculating a first checksum of the unit data having the same firstrank; extracting the unit data having an identical second rank after theconversion process from the unit data of each of the blocks andcalculating a second checksum of the unit data having the same secondrank; comparing the first checksum with the second checksum; andcontrolling the aperture array to control the plurality of chargedparticle beams according to a result of the comparing.
 16. Thenon-transitory computer readable recording medium according to claim 15,wherein the driver is provided in each group having a predeterminednumber of the controllers, further comprising dividing the unit datainto the blocks having the unit data corresponding to an output of thedriver.
 17. The non-transitory computer readable recording mediumaccording to claim 15, wherein the program causes the computer tofurther execute: dividing each of the blocks into a first block and asecond block; calculating a third checksum based on the unit dataincluded in the first block; calculating a fourth checksum based on theunit data included in the second block; and comparing the third checksumwith the fourth checksum.
 18. The non-transitory computer readablerecording medium according to claim 15, wherein the unit data include aplurality of bit data arranged based on a third rank different from thefirst rank and the second rank, the program causes the computer tofurther execute: calculating a sum of values of the plurality of unitdata as a fifth checksum; summing the bit data of the unit data in thethird rank; calculating a sixth checksum based on a result of thesumming; and comparing the fifth checksum with the sixth checksum. 19.The non-transitory computer readable recording medium according to claim18, wherein a time for defining a dose of the charged particle beam isallocated to the bit data.
 20. The non-transitory computer readablerecording medium according to claim 18, wherein, the bit data arepaired, and the bit data are arranged such that a difference of the dosedefined by the pair of the bit data is minimized between the pair of bitdata.